Automatic change-over regulator for liquefied petroleum gas equipment



R. W. THOMAS AUTOMATIC CHANGE-OVER REGULATOR FOR LIQUEFIED April 13,1943.

PETROLEUM GAS EQUIPMENT Filed June 29, 1939 2 Sheets-Sheet 1 :Il llllIIIIIIIIA IIIII- lllllllllll I! INVENTOR ROSSWELL W. THOMAS April 13,1943.

R. W. THOMAS AUTOMATIC CHANGE-OVER REGULATOR FOR LIQUEFIED PETROLEUM GASEQUIPMENT Filed June 29, 1939 2 Sheets-Sheet 2 INVENTOR ROSSWELL W.THOMAS A BY fi a o mm vwvv W it vv'vw w mm lPatented Apr. 13, 1943AUTOMATIC CHANGE OVER REGULATOR FOR LIQUEFIED PETROLEUM GAS EQUIP- MENTRosswell W. Thomas, Birmingham, Mich, assignor to Phillips PetroleumCompany, a corporation oi Delaware Application June 29, 1939, Serial No.281,969

21 Claims. (CI. 62-1) The present invention relates to improvements inchange-over devices for dispensing high pressure gas.

More specifically, it relates to improvements in automatic change-overregulator devices especially adaptable to systems for dispensingliquefied petroleum gas of the character where the installation providesat least two containers as sources of liquefied gas from which vaporsmay be drawn for use in appliances, one source being held in reserveuntil the active source is depleted.

Liquefied petroleum gas, such as propane, butane, or a mixture of thetwo, is now being sold extensively in tanks or cylinders of a portablenature. In making use of this liquefied gas for operating gas consumingappliances, such as domestic gas ranges, it is necessary to provide asuitable means for reducing the pressure of the vapor from the storagecontainer to the pressure at which the gas consuming appliances aredesigned to operate. It is also desirable to give the customer acontinuous, uninterrupted supply of gas. With these aims in view,various types of equipment have been designed to dispense the liquefiedpetroleum gas. It is customary, when portable containers are used, toprovide at least two containers as sources of liquefied gas from whichvapors may be drawn andreduced to the proper pressure for use in gasconsuming appliances, one source being held in reserve until the activesource is depleted. It is then necessary to chambers and consequentlypresents hazards associated with high pressure. Care must be used inmaking the necessary connections each time an exhausted container isreplaced with a charged container, otherwise there is a possibility ofgas leakage with its inherent hazards. Also, there is always present thedanger of subsequent failure of the tube which would allow a largeamount of highly inflammable and otherwise dangerous gas to escape.

Recently there has been inaugurated in liquefied gas retail trade a formof self-service in which the customer buys the gas in small containers,transports them to the place where they are to be put into service, andmakes the necessary connections to put the charged containers intoservice. This invention is particularly adaptable to this type ofservice, since it does not employ high pressure hose or connections, andis sufiiciently simple in operation as to en- 7 able a person who isunskilled in mechanics, for

cut oil the depleted source of liquefied gas and put the reserve sourceinto service. This may be effected by manual or automatic change-overfrom one container to the other, it being preferable to employ anautomatic device to effect this change in order to prevent anyinterruption in the gas flow which would extinguish any stoves, pilotlights, or gas lights being in use at that time. It is also of greatinconvenience to the customer to go to the containers to change thevalves each time one of the containers is exhausted.

Recently there have been developed various systems equipped withautomatic valves, whereby upon the pressure in the active containerbecoming low, the vapor in the reserve container will be drawn upon. Asystem of this type is disclosed in Patent No. 2,257,249 issuedSeptember 30, 1941. One of the chief disadvantages of such equipment isthat it is necessary to use a more or less flexible hose or tube toconnect the control devices to the gas storage chambers. This tubing,together with the necessary fittings, is subjected to the high pressureof the storage example, the housewife, to replace an exhausted containerwith a fresh container.

An important object of this invention is to provide an improvedchange-over device for dispensing high pressure gas.

A further object of the invention is to provide a change-over devicewhich will be automatic in its change-over action.

Another object of this invention is to provide a device for dispensinghigh pressure gas which may be operated with safety by those who areunskilled in mechanics, for example, the housewife.

Other objects and advantages of the invention will be apparent duringthe course of the following description taken in connection with theaccompanying drawings forming a part of the specification and in whichdrawings,

Figure 1 is a view in elevation of equipment for dispensing liquefiedpetroleum gas, including one embodiment of the present invention,

Figure 2 is a view partly in vertical section and partly in elevation ofa portion of the equipment showing the relative position of the partswhen set to effect a change-over.

Figure 3 is a vertical cross-section of one modification of theinvention.

Referring first to the form of the invention shown in Figures 1 and 2, Aand B represent containers for separate supplies of liquefied petroleumgas, C a service pipe line which may lead to any suitable gas consumingappliances, not shown in the drawings, D and E pressure regulators, Fand G conduits for establishing connection between the regulators D andE and the service pipe line through the manifold H. K

represents a second stage regulator which I prefer to use, but whichforms no part of the invention. J represents a suitable indicator deviceto notify the customer when one of the containers is exhausted.

In Figure 2, where similar characters designate similar parts, a portionof a liquefied gas or high pressure gas container is designated byreference numeral I while 2 represents the interior of this container.An annular ring 3 having a shoulder 4 is attached to the container at 5.Ring 3 is tapped to receive a plug member 6 which is drilled and tappedto contain a valve 1 of the tire valve core type. Directly above tirevalve core stem 8 is a push-pin 9. Concentric with push-pin 9 is a tubeIII which is oi. sufllcient diameter inside to provide an annularpassageway ll. Tube I0 is threaded at the top and tapered in the mannerof a truncated cone. Concentric with tube I0 is a connector |2 bored toreceive tube l0 and having its lower portion externally threaded toengage an upper tapped portion of plug member 6. Connector l2 forcestube I0 against resilient gasket l3 forming a gas tight connectionbetween tube l0 and plug member 6. Push-pin 9 is provided with a guidel4 which will not pass through passageway l5; this prevents the push-pinfrom dropping out when this assembly is disconnected from a container.

A regulator housing comprising a body Hi and a cover I! is-provided witha flexible diaphragm l8 dividing the housing into two compartments,namely a fluid compartment i9 and a loading compartment 20. Fluidcompartment I9 is provided with an inlet port 2| in communication withtube l0 and with an outlet port 22. Loading compartment 20, which isvented to the atmosphere, contains an expansion spring 23 seated in aretainer or cup 23' on the diaphragm. A diaphragm retainer 24 with athreaded connection to body l6 bears upon diaphragm slip ring 25 wh chin turn holds diaphragm l8 securely in place. Retainer 24 is so shapedas to provide a circumferential groove 26 into which screws 2! extendholding the cover II in place on the regulator body l6, but at the sametime allowing cover I! to be rotated with respect to regulator body 6.Loading compartment 20 is provided with a diaphragm stop or dampingmember 28 for controlling the efi'ective diaphragm area which in turnwill control the discharge pressure of the regulator. Diaphragm stop 28is in threaded engageissued June 10, 1941. These regulators operate asfollows:

The compression spring 23 in loading compartment 20 exerts a pressureupon diaphragm I8. The resulting downward thrust of the diaphragm istransmitted through push-pin 9 and valve stem 8 to tire valve core I,actuating the same.

High pressure gas in container I passes upwardly through the tire valvecore, in which its pressure is reduced by throttling action, through theannular passageway H and inlet port 2| to the fluid compartment I9, andthence out of the fluid compartment through outlet port 22.

Should the pressure in the fluid compartment become excessive, thediaphragm will be forced in an upward direction allowing the push-pin 9to move upwardly, which in turn will release valve stem 8 allowing thevalve 1 to close. The valve will remain closed until the pressure in thefluid compartment drops to a point where the compression spring isenabled to force the diaphragm and plunger downward reopening the valve.Constant withdrawal of vapor through outlet port 22 usually results in athrottling action by valve 1 to maintain a constant pressure incompartment l9.

Diaphragm stop 28 provides a means of controlling the pressure in fluidcompartment I9 and hence the discharge pressure of the regulator. Whenthe diaphragm stop is in a position as illustrated by regulator E ofFigure 2, all of the area of diaphragm I8 is eifective to counteract thepressure of spring 2'3. A definite pressure in fluid compartment l9 willbe required to force diaphragm l8 upward sufflciently to release valvestem 8 and allow valve 1 to close. This pressure will be referred tohereinafter as the lower pressure level. When the diaphragm stop is in aposition as illustrated by regulator D, the effective diaphragm area isconsiderably reduced and consequently a higher pressure is required inthe fluid chamber to effect the closure of valve 1. This pressure willbe referred to hereinafter as the higher pressure level.

Figure 3 illustrates one modification of this invention in which theregulator housing comprises a regulator body 40, a diaphragm clampingring 46 bolted to the body, and a cover 4| threadably connected to thediaphragm clamping ring, The regulator housing is divided by a suitablediaphragm 44 into two compartments, namely a fluid compartment 42 and aloading compartment 43.- Fluid compartment 42 is provided with an inletport 53, in communication with tube l0, and an outlet port 54 incommunication with conduit 32. Loading compartment 43, which is ventedto the atmosphere, contains an expansion spring 45 and a diaphragmbackcontact cup 23' and serve to guide cup 23' in its movement.

A conduit 32', of flexible nature, together with suitable connections 3|establishes communication between regulator outlet port 2| and amanifold 33. This manifold is provided with suitable f check valves 34and 34', a convenient outlet 35 ing plate 5|. Cover 4| is provided witha web 49 which interferes with a stop 48 on the diaphragm clamping ring46, thereby limiting the amount 01' rotation of the cover. Stop 48 asillustrated in Figure 3 is a long machine screw and is interchangeablewith any of the machine screws 41 that secure the diaphragm clampingring 48 to the regulator body 40. Push-pin 9, tube l0, and connector l2are substantially the same as corresponding parts in Figure 2. Push-pin8 is provided with a projection 50 which prevents the push-pin fromdropping out when the regulator is disconected from a cylinder.

The operation of this regulator is the same as the operation of thepush-pin type illustrated in Figure 2.

Variation of the compression of spring 45 pro- 'pend upon the force ofgravity for their operavides a means of controlling the pressure influid compartment 42 which is equivalent to the discharge pressure ofthe regulator. Diaphragm clamping ring 46 is provided with externallefthand threads which are engaged by corresponding internal threads incover 4|. When cover 4| is rotated in a clockwise direction, thelefthand thread permits it to rise slightly relative to diaphragm-44,relieving some of the compression'in spring 45 thereby reducing thepressure of the spring on diaphragm 44, Since the mount of rotation islimited by stop 48, the spring pressure on top of the diaphragm will beof a definite value causing the regulator to maintain a definitepressure in fluid compartment 42. This pressure will be referred tohereinafter as the lower pressure level. Conversely when the cover isrotated in a counter-clockwise direction, the compression in the springis increased, thereby increasing the pressure of the spring on thediaphragm. This in turn will cause the regulator to maintain a somewhathigher pressure in fluid chamber 42; This pressure will be referred tohereinafter as the higher pressure level.

In the operation of a gas dispensing system as illustrated in Figure 1,two regulators of the type disclosed in Figure 2 or Figure 3 are used.In these illustrations, these regulators are used as first stageregulators in conjunction with a second stage regulator 31 ofconventional design. Two containers A and B have been provided assources of gas, one of which is held in reserve until the other isdepleted. Suppose it is desired to withdraw gas from container A holdingthe fluid in container B in reserve until container A becomes virtuallyexhausted.

Regulator D is' adjusted to operate at its higher pressure level, forexample twelve pounds per square inch, while regulator E is adjusted tooperate at its lower pressure level, for example eight pounds per squareinch. It is evident, since both regulators are in communication with acommon manifold H, that there will be no flow from regulator E to themanifold. Therefore, as the customer draws upon the gas supply,withdrawing gas through service line C, gas will be withdrawn fromcontainer A through regulator D, conduit F, manifold H, and second stageregulator K. Gas will be withdrawn from container A until it becomesexhausted or until its pressure drops to the point where it will nolonger maintain a pressure in manifold H higher than the lower pressurelevel. When the pressure in the manifold drops below the lower pressurelevel,

gas will be withdrawn from container B due to the action of pressureregulator E, effecting an automatic change-over of withdrawal fromcontainer A to container B. A suitable indicator J, by responding to thechange in pressure in manifold H, notifies the customer that container Ais exhausted. Container A is then replaced with a charged container. Ifit is now desirable to hold container A as a reserve source of gas untilcontainer B is exhausted, regulator D is adjusted to operate at thelower pressure level while regulator E is adjusted to operate at thehigher pressure level. This will insure selective withdrawal fromcontainer B until it becomes exhausted whereupon an automaticchange-over of withdrawal-will be made from container B to container A.

It is obvious that the gas pressure regulators described herein could bemodified so as to contain regulator valves as an integral part of theirmechanism. Since these regulators do not detion, it is evident that they'will operate equally well in any position. Since the gas in thecylinder is usually in liquefied form it will be obvious that if thewithdrawal is made below the surface of the liquid the first reductionin pressure will vaporize the-liquefied gas. This would be the case forexample where the containers are in the position shown in Figure 1inverted.

While I have herein described and illustrated two modifications of myinvention which are to be taken as preferred examples, it is to beunderstood that various changes may be made in size, shape, andarrangement of parts withoutdeparting from the spirit of my invention asexpressed in the following claims.

I claim:

1. In a system for storing and utilizing high pressure gas thecombination comprising, a pmrality of. containers for the gas, a serviceline, a conduit connecting each container to the service line, a gaspressure regulator interposed in each conduit at the container end ofthe conduit, each gas pressure regulator having an external adjustmentmember for governing the outlet pressure of the same, the member havinglimited movement between two extreme positions.

2. In a system for storing and utilizing high pressure gas, thecombination comprising, a plurality of containers for the gas, a servicline, a conduit connecting each container to the service line, a gaspressure regulator interposed in each conduit at the container end ofthe conduit, each regulator including an adjustment member forcontrolling the outlet pressure of the sam having two extreme positionsfor producing a high and a low outlet pressure, the high and the lowoutlet pressures being substantially the same for the regulators.

3. In a system for storing and utilizing high pressure gas thecombination comprising, a pair of containers for the gas, a serviceline, a conduit connecting each container to the service line, a gaspressure regulator interposed in each conduit at the container end ofthe conduit for reducing 4. In a system for storing and utilizinghighpressure gas, the combination comprising, a plurality of containersfor the gas, a service line, a conduit connecting each container to theservice line, a gas pressure regulator interposed in each conduit at thecontainer end of the conduit, each regulator including anadjustmentmemberfor controlling the outlet pressure of the same having two extremepositions for producing a high and a low outlet pressure, the differencebetween the high outlet pressure and the low outlet pressure being smallrelative to the pressure in the container.

5. In a system for storing and utilizing high pressure gas, thecombination comprising, a plurality of containers for the gas, a serviceline, a conduit connecting each container to the service line,'a gaspressure regulator interposed in each conduit at the container end oftheconduit, each regulator including an adjustment member-for controllingthe outlet pressure of the same having two extreme positions forproducing a high and a low outlet pressure, the diiference between thehigh outlet pressure and the low outlet pressure 6. In a system forstoring and utilizing high 7 pressure gas, the combination comprising, aplurality of containers for the gas, a consumers service line, a conduitconnectingeach container to the consumer's service line, a valveadjacent the container end of each conduit and havinga gas inlet sideand a gas outlet side, a valve operating member associated with eachvalve normally urged into valve opening position, gas pressure operatedmeans in communication with each conduit on the outletside of the valvecoacting with the valve operating member to change the position or thesame in response to change in pressure, adjustment means associated withthe gas pressure operated means and having limited movement between twoextreme positions.

7. In a system for storing and utilizing high pressure gas, thecombination comprising, a plurality of containers for the gas, aconsumer'sservice line, a conduit connecting each container to theconsumer's service line, a valve adjacent the container end of eachconduit and having a gas inlet side and a ga outlet side, a valveoperating member associated with each valve normally urged into valveopening position, gas pressure operated means in communication with eachconduit on the outlet side of the valve co-acting with the valveoperating member to change the position of the same in response tochange in pressure,

adjustment means associated with the gas pres-' sure operated means andhaving limited movement between two extreme positions.

8. In a system for storing and utilizing high pressure gas, thecombination comprising, a plurality of containers for the gas, aconsumer's service line, a conduit connecting each container to theconsumer's service line, a valve adjacent the container, end of eachconduit and having a gas inlet side and a gas outlet side, a valveoperating member associated with each valve normally urged into valveopening position, a diaphragm in communication with the outlet side ofthe valve, the diaphragm having co-action with the valve operatingmember such that the position of the valve operating member is changedin response to change in pressure on the diaphragm, and a housing forthe diaphragm having a rotatable section and means acting between therotatable section and the diaphragm to change the pressure response ofthe diaphragm on rotation of the duit co-acting with the spring means tooperate I the valve.

10. In a system for storing and utilizing fluid under pressure,comprising a plurality of containers for the fluid, a service line,condults.connecting the interior of the containers to the service line,a control valve in each conduit adjacent the container end, each valvehaving an inlet side and an outlet side; a diaphragm in communicationwith each conduit on the outlet side of the control valve movable inresponse to pressure changes in the conduit, valve operating elementsacting between the diaphragms and the control valves on movement of thediaphragms, resilient means acting on each diaphragm tending to move thesame into valve opening position, and additional means independentlycoacting with the diaphragms to change the relative pressure responsecharacteristics of the diaphragms.

11. In a system for storing and utilizing fluid under pressure,comprising a plurality of containers for the fluid, a service line,conduits connecting the interior of the containers to the service line,a control valve in each conduit adjacent the container end, each valvehaving an inlet side and an outlet side, a check valve in each conduiton the outlet side of the control valve to prevent reverse flow throughthe conduit, a diaphragm in communication with each conduit on theoutlet side or the control valve movable in response to pressure changesin the conduit, valve operating elements acting between the diaphragmsand the control valves on movement of the dlaphragms, resilient meansacting on each diaphragm tending to move the same into valve openingposition, and additional means independently co-acting with thediaphragms to change the relative pressure response characteristics ofthe diaphragms.

12. In a system for storing and utilizing fluid under pressure,comprising a plurality of containers for the fluid, a service line,conduits connecting the interior of the containers to the service line,a control valve in each conduit adjacent the container end, each valvehaving an inlet side and an outlet side, a diaphragm in communicationwith each conduit on the outlet side of the control valve movable inresponse to pressure changes in the conduit, valve operating elementsacting between the diaphragms and the control valves on. movement of thediaphragms, resilient means acting on each diaphragm tending to move thesame into valve opening position, and a diaphragm restraining elementfor each diaphragm movable into contact with the diaphragm to change thepressure response characteristic of the same.

13. A system for storing and utilizing high pressure fluid comprising aplurality of containers for the fluid, a service line, a plurality oflow pressure hoses connected to the service line, a connection memberfor fluid withdrawal on each container, a connector on the free end ofeach hose removably connected to the container at the connection member,and a pressure reducing means associated with each container forreduclng the pressure of the fluid withdrawn therefrom.

14. A system for storing and utilizing high pressure fluid comprising aplurality of containers for the fluid, a service line, a plurality oflow pressure hoses connected to the service line, a connection memberfor fluid withdrawal on each container, a connector on the free end ofeach hose removably connected to the container at the connection member,check valve means for preventing back flow of fluid through the hoses,and a pressure reducing means associated with each container forreducing the pressure of the fluid withdrawn therefrom.

15. A system for storing and utilizing high pressure fluid comprising aplurality of containers for the fluid, a service line, a plurality oflow pressure hoses connected to the service line. a connection memberfor fluid Withdrawal on each container, a connector on the free end ofeach hose removably connected to the container at the connection member,a valve associated with each connection member closing the container,and gas pressure operated means in communication with the hose andhaving a valve operating member for opening and closing the containervalve associated therewith.

16. A system for storing and utilizing high pressure fluid comprising aplurality of containers for the fluid, a service line, a plurality oflow pressure hoses connected to the service line, a connection memberfor fluid withdrawal on each container, a connector on the free end ofeach hose removably connected to the container at the connection member,a valve associated with each connection member closing the container, avalve operating member associated with each connector for opening andclosing the valve, and a gas pressure operated means in communicationwith each hose for actuating the valve operating member.

17. In a system for storing and utilizing high pressure gas, thecombination comprising a plurality of containers for the gas, a serviceline, a conduit connecting each container with the service line, a gaspressure regulator in each conduit, each regulator including anadjustment member for controlling the outlet pressure of the samebetween upper and lower values, one of the regulator being set at arelatively high outlet pressure at the same time another is set at alower outlet pressure.

18. In a system for storing and utilizing high pressure gas, thecombination comprising a pluiality of containers for the gas, a serviceline, a conduit connecting each container with the service line, a gaspressure regulator in each conduit, each regulator including anadjustment member for controlling the outlet pressure of the same,having two extreme positions for producing a high and a low outletpressure, the high and the 10w outlet pressure being substantially thesame for the regulators, one of the regulators being set at a relativelyhigh outlet pressure at the same time another is set at a lower outletpressure.

19. In a system for storing and utilizing high pressure gas, thecombination comprising a plurality of containers for the gas, a serviceline, a conduit connecting each container with the service line, a gaspressure regulator in each conduit, each regulator including an externaladjustment member for controlling the outlet pressure of the samebetween upper and lower values, one of the regulators being set at arelatively high outlet pressure at the same time another is set at alower outlet pressure.

20. In a system for storing and utilizing high pressure gas, thecombination comprising a plurality of containers for the gas, aconsumers service line, a conduit connecting each container with theservice line, a valve controlling each conduit and having a gas inletside and a gas outlet side, a valve operating member associated witheach valve normally urged into valve opening position, gas pressureoperated means in communication with each conduit on the outlet side ofthe valve coacting with the valve operating member to change theposition of the same in response to change in pressure, adjustment meansassociated with the gas pressure operated means and having limitedmovement between two extreme Positions.

21. In a system for storing and utilizing high pressure gas, thecombination comprising a plurality of containers for the gas, aconsumers service line, a conduit connecting each container with theservice line, a valve controlling each conduit and having a gas inletside and a gas outlet side, a valve operating member associated witheach valve, spring means associated with each valve operating membernormally urging the same into valve opening position, gas pressureoperated means in communication with each conduit 0n the outlet side ofthe valve coacting with the spring means to operate the valve, externaladjustment means acting on said spring means and having limited movementbetween two extreme positions to selectively act on said spring means inan opposite manner.

ROSSWELL W. THOMAS.

